Re: Do NOT upgrade to palo v2.10

[James Bottomley <James.Bottomley@HansenPartnership.com>]

On Tue, 2019-07-30 at 14:30 -0700, James Bottomley wrote:
> On Tue, 2019-07-30 at 22:58 +0200, Helge Deller wrote:
> > PALO version 2.10 was released last week, but it has a bug
> > which may prevent that you are able to boot your kernels:
> > 
> > Entry 000e0000 first 000e0000 n 2
> > Segment 0 load 000e0000 size 8249207 mediaptr 0x1000
> > Abort: Would overwrite palo 00060000-000f8e30 or data 3faef580
> > areas.
> > ERROR: failed to load kernel
> 
> Ah, that's unfortunate.  It must be an artifact of compressed kernels
> because my uncompressed one boots here:
> 
> Entry 00100000 first 00100000 n 5
> Segment 0 load 00100000 size 508616 mediaptr 0x1000
> Segment 1 load 0017d000 size 370864 mediaptr 0x7e000
> Segment 2 load 00200000 size 12026224 mediaptr 0xd9000
> Segment 3 load 00d79000 size 3850884 mediaptr 0xc52000
> Segment 4 load 01200000 size 2690120 mediaptr 0xfff000
> Loading ramdisk 24263780 bytes @ 3e8ca000...
> 
> which would be why I never saw this.

This is what I'm currently testing as the fix; it reduces the bss from

  6 .bss          0008d8b0  0006b580  0006b580  0000b5f8  2**6
                  ALLOC

To

  6 .bss          0003d8b0  0006b600  0006b600  0000b654  2**6
                  ALLOC

Which will get us under 0x000e0000 assuming that's the lowest address a
kernel can be loaded at ...

James

---
diff --git a/ipl/ext2.c b/ipl/ext2.c
index 31b8469..d8b0c2f 100644
--- a/ipl/ext2.c
+++ b/ipl/ext2.c
@@ -475,17 +475,25 @@ static int ext3_extent_node_find(struct ext2_inode *ip,
 static int ext3_extent_load_find(struct ext2_inode *ip, int leaf, int d,
 				 int blkoff)
 {
-	static char blockbuf[EXTENT_MAX_DEPTH][EXT2_MAX_BLOCK_SIZE];
+	static char *blockbuf;
 	static int cached_blockno[EXTENT_MAX_DEPTH];
 	struct ext3_extent_header *hdr;
 
-	hdr = (struct ext3_extent_header *)blockbuf[d];
+	if (!blockbuf) {
+		blockbuf = malloc(EXTENT_MAX_DEPTH*EXT2_MAX_BLOCK_SIZE);
+		if (!blockbuf) {
+			printf("Failed to allocate memory for block buffer\n");
+			return -1;
+		}
+	}
+
+	hdr = (struct ext3_extent_header *)&blockbuf[d * EXT2_MAX_BLOCK_SIZE];
 	if (cached_blockno[d] != leaf) {
 		printf("load extent tree[%d] block at %d\n", d, leaf);
 
-		if (cons_read(dev, blockbuf[d], sizeof(blockbuf[d]),
+		if (cons_read(dev, hdr, EXT2_MAX_BLOCK_SIZE,
 			      leaf * ext2_blocksize) !=
-		    sizeof(blockbuf[d])) {
+		    EXT2_MAX_BLOCK_SIZE) {
 			printf("ext3_extent_load_find: read error\n");
 			return -1;
 		}
@@ -504,7 +512,7 @@ static int ext3_extent_load_find(struct ext2_inode *ip, int leaf, int d,
 		return -1;
 	}
 	if (sizeof(hdr) + sizeof(struct ext3_extent)*hdr->eh_entries >
-	    sizeof(blockbuf[d])) {
+	    EXT2_MAX_BLOCK_SIZE) {
 		printf("ext3_extent_load_find: extent is larger than buffer\n");
 		return -1;
 	}